Static gas turbines are usually equipped with filters, arranged in the intake duct or in an intake housing, for the purpose of purifying the ambient air drawn in by the compressor. In this context, a plurality of filters are often connected one after another and free the drawn in ambient air, also called intake air, initially from relatively coarse dirt particles and then from relatively small dirt particles. Purifying the intake air is necessary on one hand in order to avoid deposits on the compressor blades and associated ageing processes in the compressor which would lead to a reduction in the efficiency of the compressor and thus to a reduction in the efficiency of the gas turbine. It is also necessary that particularly pure cooling air is provided to the hot gas components employed in the turbine as, without this, deposits could jeopardize reliable cooling of the components.
It is also known that, as well as the energy required for immediate electricity generation, static gas turbines must also often keep power reserves ready in order to be able to limit those fluctuations which are present in the electrical distribution grid in the form of changes in the grid frequency. In this context, it is known that, for what is referred to as frequency support, power reserves can be mobilized and made available at short notice, in that, upstream of the compressor inlet, a fluid is introduced, thus increasing, at short notice and for a short period, the mass flow rate and thus the power output of the gas turbine. This method is known as frequency support by wet compression.
It is further known, during rated operation of the gas turbine, to overfire the gas turbine for a short time and thus raise the power output of the gas turbine to above 100% of the rated load, in order to carry out the required grid support. Such frequency support measures initiated for this purpose usually last for no longer than 15 minutes as, during this time, further grid support measures are brought in and taken such that the quick reaction—wet compression or overfiring—of the running installations can be withdrawn.